Quieter PCs

[Will be adding pictures later.]

Since my
Quiet P4 document
of several years ago, I've built two newer desktop computers,
one as a backup (spare desktop) and one as a replacement for my main desktop.
(Like my earlier PC writings, this one will become obsolete after I write it
and seem quaintly anachronistic within a couple years. Technology marches
very quickly.)
The big story is improvements to the main desktop machine,
but let's start with the backup which gave valuable experience
with the Antec "Performance" line of quiet cases.
The backup is actually the second most recent computer.

Backup Desktop: Pentium 4 2.4 in Antec P150

The backup recycled an old, but sturdy and reliable
Intel D850EMV2 motherboard and Pentium 4
2.4 with 512MB of Rambus memory. I got a BFG GeForce 6600 GT OC AGP 128MB
as basically the only AGP board I could find with two Dual DVI digital
video outputs for use with newer dual LCD monitors. It also turns
out that the Nvidia video drivers are very well supported under
FreeBSD (and Linux and Windows). The machine is set up as dual boot
FreeBSD and Windows. It usually runs FreeBSD.

CPU cooler is an Arctic Cooling Super Silent 4TC like I used on my original
P4 1.8. It runs a bit hotter on the 2.4 than on the 1.8, but the fan turns
slowly at low loads due to the temperature control (via a thermistor stuck into
the heat sink fins) and speeds up for higher loads.
It works well and is very quiet.
(The 4TC is slightly better suited to
slower CPUs like the 1.8, but worked fine in the 2.4. It was not really
adequate for a P4 3.2 where it ran too hot and the fan turned too fast
most of the time.)

Video cooler is actually a new, closeout Arctic Cooling AMD CPU cooler which I
thermal epoxied
(Arctic
Alumina Adhesive
thermal epoxy) to the main GPU chip.
I also thermal epoxied some sheet aluminum to the video RAM chips, and
epoxied those to the AMD cooler. The sheet aluminum went onto the RAM first,
since it's lower on the board than the GPU chip. In other words, the sheet
Aluminum was used as a shim to make the RAM chips the same height off the board
as the GPU chip. The shims were allowed to fully cure first.
Then the heatsink was epoxied to the GPU and RAM shims.
The sheet aluminum and heatsinks were properly
scruffed up with sandpaper then cleaned with ethanol
before epoxying.

Needless to say, the shims and heat sink had to be carefully positioned to make
everything fit the board and computer, since this was all a non-standard
use of the cooler.
The cooler had way more heat dissipation than was needed, and was somewhat
too heavy for the video card. To help support the weight, I ran some zip
ties from the unsupported
corner of the card to the power supply bracket above.
The other slight mistake is that I didn't press down hard enough
on the epoxy when it was curing,
so the epoxy may have been a little thicker than ideal.
Remember that thermal compounds should be as thin as possible.
The closer the heat sinks are to what they are cooling, the better.
More, thicker thermal compound is bad since the compound itself
doesn't conduct heat as well as the chips or the heat sinks.
It should always be a thin as possible.

The real secret of the computer is the Antec P150 case which a friend
told me about. This is a Mini-ATX case with much of the same design
thinking as the Antec P180 and P182 quiet cases.
It is an all-steel case with
vibration damping on the side panels, one large, slow turning 120mm
exhaust fan, and a front panel which blocks direct sound output from
the front air vents while still allowing plenty of air in via the
side air intakes formed at the left and right sides of the plastic
front panel. In other words there are two front panels: a metal one
that's part of the case and has the front-facing air intakes,
and a plastic one that has side-facing air intakes. The plastic front door
blocks much sound from coming directly out of the metal front panel.
Another major noise reducer are the very soft Silicone hard disk mounts.
They decouple much of the drive vibration from the case.

There are many other finely-engineered sound, thermal and airflow details
that are too much to go into here, but this case is very, very well
thought out, quiet, and easy to work with. It's even pretty sleek-looking
in a contemporary, consumer-industrial sort of way.
The P150 is an excellent design that's probably only exceeded by the P180/P182.

Unfortunately the original P150 has been discontinued
and modified slightly as the renamed Antec Solo.
Solo loses the hidden optical drive doors that P150 had,
and thus loses one of the sound barriers.
It may be a little noisier as a result.
No idea why Antec had to mess with a good thing.
I'd call it a mistake to do so.

Main Desktop Gets Series Of Upgrades, Liquid-Cooling

My main desktop was upgraded in several stages.

Since the Arctic 4TC wasn't enough cooler for the P4 3.2 on a
new ASUS P4T-E motherboard, the CPU got a Thermalright XP-120 cooler
in November 2004.
Video was upgraded to ATI Radeon 9800 Pro 128MB around August 2004.
Unfortunately one of the
heat pipes in the otherwise nice Thermalright design eventually
failed around September 2005 and burned the motherboard CPU socket,
making the motherboard useless.
The CPU still worked in a new ASUS P4C800-E Deluxe motherboard.
CPU cooler was again a XP-120 which Thermalright replaced under warranty
since the original one had failed less than one year from new.
They did not pay for the new motherboard.
Ran everything air-cooled for a while,
but my faith in the reliability of heat pipes and heat sinks
which depend on heat pipes was burned like the board.
Since that CPUs kept getting hotter, and most of the big, new air-cooled heat
sinks designed to cope with them seem depend heavily on heat pipes:

The next stage was to liquid-cool the P4 3.2 and ASUS P4C800-E Deluxe
and Radeon 9800 with a Swiftech Apex Ultra Plus kit purchased from
SVC.
This kit had the Apogee GT CPU water block, MCW60 VGA water block,
MCW30 northbridge waterblock, MCP655 water pump, MCR220 dual length radiator,
etc. The Swiftech kit is excellent. The Apogee cooler uses a low resistance,
computational-fluid-dynamics-optimized, machined-copper-pin array.
The MCW60 was essentially one of Swiftech's older CPU coolers and
it too worked very well on the video card.
The 220 radaiator is twice as long as the typical radiator (at the time)
meaning two large 120mm fans could be used at lower speed to have more cooling
at lower noise. Since then, triple and quadruple length radiators have
come out, but probably mainly to deal with the growing component heat.
There are also passive radiators with no fans that look and function
somewhat like small room heaters.
Also changed to a Western Digital 120 GB SATA drive.

I built my own acrylic external radiator box that mounted 4 Arctic Cooling
Fan 12 120mm fans in push pull (two fans pushing, two fans pulling), and
used a Cooler Master Aerogate 3 fan controller to run them at
600 RPM for regular
desktop use, and optionally cranked them up to about 1000 RPM for gaming.
The radiator box has half-round radiusing on the input to enable a smooth,
hemispherical airflow, just like NASA's big wind tunnels.
The radius lowers the input impedance, meaning air can be more efficiently
pulled in.
Indeed air can be felt being pulled in smoothly from the
front around to the sides of the intake radius, exactly as hoped for.
Conveniently,
TAP Plastics
sells half-round acrylic rods (think "D" shape
or half of a circle) which I miter-framed and
bonded to the front edge of the box.
(Acrylic cement melts the plastic, so it's basically like chemical welding.
The end result is actually a new, solid piece of plastic, not pieces
of plastic glued together.)
The external radiator box has Sorbothane feet for vibration
absorption and sits on top of the case.
The Arctic Fan 12s have open frames and an internal soft suspension
that isolates the motor and fan from the frame.
They're basically silent at low speeds,
and no other fans have their excellent, patented design.

Temperatures for regular computing (basically idle) were in the 30 to 40
Celsius range.
Very cool and very quiet.
Pump is fairly quiet at middle speed setting of 3.
Quieter (almost silent) at slowest "1" and slightly noisier at highest "5".

After dropping a screw on the nicely working, but aging and no longer
competitively fast P4 3.2/ASUS, replaced the motherboard, CPU,
memory and video card, power supply and disk drive.
Pretty much had to replace them all since the old memory, AGP video,
power supply, etc.,
would not work with any current replacement parts. Stuff changes too fast
for parts that are a few years old to be usable with anything readily
available in stores. It's annoying but inevitable thanks to Moore's law.
But it also means getting a much faster computer each time.

After research ended up getting EVGA 680i motherboard,
Intel E6600 Core 2 Duo 2.4 (Conroe family),
EVGA 8800 GTS video with 640 MB RAM,
2GB of OCZ PC8500 with custom heatsinks,
Seasonic S12 650 power supply.
Had to get a new water block for the new video card and got the
Koolance VID-280.
The Danger Den 8800 GTS waterblock may be a bit better,
but the Koolance is good.
Both cool all the major heat sources on the video card:
the main GPU chip, RAM, voltage regulators, etc.
Used a new Danger Den 680i northbridge cooler and moved the
Swiftech MCW30 to the southbridge.
(Nvidia doesn't use the two chips the same way as Intel uses
their northbridge and southbridge and doesn't call them the same
names, but I tend to think of them as being roughly equivalent.
In both cases,
the chip near the CPU essentially controls the flow of data
over busses between memory, CPU and peripherals,
and the other chip nearer the peripherals is more like
an application and peripheral controller.)
Be sure to get factory hard mount kits for all your chipset waterblocks.
They're convenient and much less likely to risk damage to the motherboard.

Note that the motherboard and video card are essentially made under contract
for Nvidia in Taiwan and resold to EVGA and others.
So, some companies selling Nvidia-based hardware may actually be reselling
Nvidia-contract-manufactured boards. There's nothing wrong with that, and it
probably makes quality control, support, design costs, etc., better,
but it's probably with pointing out.
EVGA has been excellent to work with.

Changed drives to Seagate Barracuda 7200 RPM 300GBs in RAID 1
for quietness and reliability. The motherboard supports SATA
at 3Gb/s, and the drives support native and tag queuing.
The Barracuda 7200s are considered to be relatively quiet and reliable.
They do seem quieter than my old Western Digitals.
The MCW60 is currently unused.
Sound is still handled by a Creative Labs Sound Blaster Audigy2 ZS at
96kHz/24-bit via S/PDIF over Toslink digital output to my
audio system.

Power supply was rated as quietest available at the time on
Mike Chin's
Silent PC Review,
which is a font of information about quiet computers and
was a major impetus behind the design and success of
the quiet Antec Performance cases.
Got the S12 650 thinking I might go SLI at some point, but even
a single 8800 GTS is massive overkill for the old games I play.
It does the Counter-Strike Source test at 250 frames per second
without the second SLI board, for example.
It renders Battlefield 2 at the highest resolutions and highest quality
settings faster than my 1600 x 1200 ViewSonic PS790 main monitor can display.
So a lower wattage power supply probably would have been ok,
and slightly more efficient too.
(The S12 650 is rated at 80%+ efficiency, but is oversized in my application.
Switching Power supplies are usually slightly less efficient when under-loaded.)

Most recently have moved the components into an Antec P180 v1.1 case,
which is basically the same as the P182, in that it has the same cable
management, water tube grommets, interior sheet steel on side and front panels,
etc.
P180/P182 is a very interesting case design which puts the power supply
and hard drives in their own lower tunnel. This is smart because it means
the main heat-generating components, which are on the motherboard,
won't heat up the air the power supply uses to cool itself.
It also means the main part of the
computer only sees the heat of its own components and not the power supply.
(This is less relevant in a liquid-cooled system,
since the liquid effectively takes the heat out of the case,
i.e., without significantly heating up the air inside the case.)
The design also means that the hard drives are cooled by the power supply fan
drawing air from the front of the tunnel, over the hard drives, before
cooling the power supply. Very clever.

Like the P150 (and probably other Antec cases) the P180 uses the front door
as a baffle, blocking most of the direct sound while having a
huge air intake area at the sides of the door.
The large area means lower air velocity for the same airflow volume.
Lower velocity usually means lower noise, which is the same reason
two large, slow-turning exhaust fans are used at the rear and top
of the case.

Regarding the side and front panels, the original P180 had a single
sheet of steel on the outside of a plastic core.
The current P180 and P182 have a steel, plastic and steel sandwich
for the side and front panels, which forms constrained-layer-damping,
as I used Dynamat Super on my old Cooler Master case.
With contrained-layer-damping, a higher-density material is
used on the outsides and a lower-density material is used on the inside.
Essentially this traps impinging vibrations into the middle layer
and dissipates it, reducing the noise and vibration transmitted to the
outside of the case.
Said another way,
the soft center layer of the sandwich acts like a one-way trap for sound
caught between the harder metal panels on the outside.
The relatively soft plastic dampens the sound as it bounces
back and fourth between the metal.
Sound gets trapped between the metal panels and can't get out.

With its dual chambers, the P180/2 is a a few centimeters
taller than a regular case.
The P180/P182 also has Silicone hard drive mounts,
which seem to greatly reduce transmission of hard drive noise to the case,
but it has two hard drive cages mounting three drives in the upper cage
and four in the lower cage.
Putting hard drives in the lower cage is recommended by Antec
for quietest operation.
It has four 5.25 inch optical drive bays and top and one 3.5 in bay below them.

Added an
mCubed
bigNG
intelligent fan controller.
(For reference, it uses 4 IRF FR024N MOSFETs (nominally about 30W devices)
and a LM75A temperature watchdog,
(monitor) under a heatsink,
along with a ULN2003A driver, FT232BL USB UART,
and Atmel ATMEGA16 controller.
It also runs way to hot in linear mode and way to noisy in PWM mode.
Could be improved with LC filtering for the PWM
and a higher switching frequency way above the audio band.)
This causes the waterblock to bow out in the middle, forcing greater
contact with the hottest portion of the CPU heat spreader.
Swiftech measures a lower thermal coefficient that way.

Changed to
IC Diamond 7
thermal paste, which has 7 carats of 40,000 mesh
diamonds at a 94% diamond loading.
Got the IC Diamond 7 from a new store:
Petra's Tech Shop
The Diamond 7 seems to have dropped all temperatures by about 3 degrees
celsius, in line with a large survey of users, and that's a huge drop.
The entire system seems to run cooler now.
The new coolant below may also make a difference, but the thermal paste
probably makes a larger difference since it's a major impedance change
directly at the heat source.

Changed to
FluidXP+ HP non-conductive,
non-corrosive, non-toxic coolant, picked up from SVC.
(HP may no longer be a current model of coolant.)
No ingredients are listed, but it's said to use all food-grade materials.
I'd guess it uses Proyplene Glycol which is non-toxic, used in
food (it's a sweetener in Mountain Dew; read the label some time :)
and has thermal properties similar to Ethylene Glycol which is toxic.
Glycerine is also mentioned as an ingredient in one of their FAQs.
The fluid is visibly more viscous than water or water and Ethylene Glycol.

CPU temperature is now 29 C with radiator fans and pump at maximum speeds.
GPU is 39 C under the same conditions.
That's with room temperature at about 22 C.
At their slowest, quietest speeds temperatures
are about 34 C and 45 C respectively.
All are with the computer esssentially idle.
These are temperatures shown by on-board monitoring so they're
uncalibrated, etc.

Changed the stock P182
Antec
Tri-cool
top and rear fans with
Arctic
Fan 12PWM
The Tri-cool is a surprisingly good mass-market fan at low speed,
but I have better.
The Arctic PWM fans are controlled by the motherboard BIOS,
varying fan speed according to CPU temperature.

Changed the lower middle fan from stock Tri-cool
to Scythe Slipstream 1200 RPM and added another one as a front upper fan.
These two fans are off for normal office use, but get switched on starting
at low speed by the mCubed when things heat up due to gaming or hot room air.
They're controlled on a curve so their speed ramps up as things get hotter.
(The Scythe Slipstream fans are extremely quiet. The Scythe
S-FLEX fans are nearly as quiet, but have some thrum probably due to
straight struts.)
With the lower middle fan off, the hard drives and power supply are
cooled only by the power supply's own fan. Mike Chin thinks this
is quieter and good enough thermally, and he may be right.
In any case, with the lower middle
fan kicking in when things actually heat up, things should be fine.

Changed to a
Danger
Den CPX-Pro
pump, which is nominally a fixed speed 12 Volt pump.
Got it from Petra's, though it's generally available from
Danger Den sellers.
It's rated at 800 liters per hour of flow rate
and a pump head of 4 meters.
My sample starts and runs at 5 Volts.
It has a 3 pin fan header and uses a maxiumum of 18 Watts of power,
so it's controlled by the mCubed,
which can handle a claimed 20 Watts in analog mode.

The CPX-Pro pump is mounted on Petra's
"Gel-Stuff"
Vibration Absorption Block, which is described as a
Latex-free Thermoplastic Elastomer about a half inch thick.
"[W]e have yet to find anything that nullifies pump vibration
better than Petra'sTech Gel-Stuff", says Petra's.

The mCubed also controls the four radiator box Arctic 12 fans.
Given that it has 20 Watts of capacity per channel,
7 Watts worth of fans should cause it no trouble.
(Those 4 fans will probably be running at less than 3 Watts total
most of the time.)

The Memory Cooling Problem

While it may be possible to cool typical desktop memory just by dumping
the heat to the surrounding air in a disorganized, ad hoc way,
memory heat dissipation seems to be a major weakness of the escalating
clock rates of higher-performance memory.
Memory busses capable of 1066 or 1333 MegaHertz
are becoming commonplace,
but memory that can actually operate
at those rates is comparitively rare, expensive and unusual.
The high heat is largely due to the voltages that need to be run higher
to keep the memory stable at elevated speeds,
and both the higher frequencies and
higher voltages result in much greater heat. (Since the normal operating
voltages are now so low, like 1.8 Volts, increasing that to say 2.4 volts
means roughly one third more heat due to the higher voltage alone.)

I got some higher-speed OCZ PC8500 memory, with a 1066 clock to match
the motherboard's 1066 FSB. In principle the best performance happens
when the memory and FSB clocks match.
I actually had one stick of the OCZ memory fail, probably due to overheating,
and without overclocking it.
OCZ kindly replaced it under warranty.
Most likely the meager heatsinking failed.
The stock heatsinking consisted of a couple pieces of perforated sheet
aluminum stuck to each other with thermal tape, with thermal tape attaching
it to the memory chips.
So I looked into ways to cool the memory better.

OCZ and possibly others do sell factory memory modules with liquid cooling
ports.
There are aftermarket water cooling systems also,
usually with 1/4 inch (6mm) hose support. I didn't like the small tubing
sizes and the additional adapters and backpressure entailed.
I considered making some home-made water cooling with larger tubing, but
the memory sockets really aren't meant to support much force.
(The big tubing is stiff and puts a strong spring force on anything
attached to it.)

Some of the fastest memory is sold with something more like real heat sinks.
They appear to be using crosscut Aluminum
extrusions of a couple millimeters thickness
extending well above the modules, but even those look fairly minimal.
Corsair and others also sell fans to blow air over those heatsinks,
which probably does improve their heat dissipation somewhat.
I listened to the OCZ memory cooling fan at Petra's and it was very quiet.
It may be a viable solution for me if it will fit over my modified modules.

I decided that air cooling was probably the most compatible with
the sockets and found the largest Aluminum heat sinks that would still allow
air to pass between the single pair of dual channel OCZ memory I was
using. With a single pair, the modules use alternate sockets on the
Nvidia motherboard, so that helped in space available. It also means
I won't be able to fully populate 4 sticks since my current modules block
the empty memory slots. I don't expect to need more than 2GB of RAM
any time soon. I basically use my main desktop for simple applications
and games. My heavy computing is done on FreeBSD servers in datacenters.
I also hope and expect to never use Windows Vista.
The BGA heatsinks are 28 x 28 x 9 mm and
are meant to cool old/low-end processors or support chips.
They were bought online as surplus.
I haven't found a Thermalloy part number for them,
but they are some large heatsink manufacturer's standard part.
The original OCZ heatsinks, as on most RAM, are thin sheet metal.

The original heatsinks and thermal tape were carefully removed
with a lot of mechanical tinkering, Goof Off and ethanol solvents.
The Arctic Alumina ceramic thermal epoxy was used as sparingly as possible;
about a third of a grain of cooked rice or less per chip.
Even then, some epoxy oozed out under full pressure, which is a good thing.
Thermal compounds should be as thin as possible, and if some is oozing out,
then that means the amount between the chip and heatsink should be minimal.
Use as little as possible and press hard when it's curing.

As if to prove a point, I stupidly left the fan off the RAM while
playing some games, thinking the big heat sinks may afford enough cooling
without it, but the PC8500 RAM seems to have burned up.
Apparently the BGA heat sinks do need more airflow than the ambient
airflow inside the case to cool things properly.
Video started to have frozen frames, black backgrounds, etc., and
eventually the system would not boot, giving a BIOS memory error "C1".
Replacing the memory with Crucial Ballistix PC6400 low latency (4-4-4-12)
on sale at Frys for $30 after rebate, the system works perfectly again.
I'm using all automatic/optimal settings, which are actually 5-5-5-15.
Supposedly this RAM overclocks well, but I don't want to risk the
system crashing again, so I probably won't overclock anything at all.
Trying to decide how to cool the new RAM.
Currently it has stock sheet metal heat sinks
and a 120mm fan blowing down on it.
May use BGA heat sinks and a shrouded fan, per the original plan
but need to design and construct the shroud.
These Crucial modules are 8 chip (single-sided) versus the 16 chip
(double-sided) OCZ, which is nice since it means only one side of
each module needs to be cooled. So half as much heat-sinking is needed.

With the BGAs, the memory temperature is well below 40 Celsius
under gaming load.
With the stock sheet metal heat sinks, the temperatures go above 40 Celsius.
Both are measured with a temperature probe on the heat sinks right next
to the chips, and with the 120mm Scythe fan blowing in free air
several inches away at medium speeds.
That's with the fan hanging in free air with no air shroud on the memory.

Speaking of servers, server boards handle memory cooling better than
desktop boards. For that matter the thermal design of server boards
is far superior to most desktop boards. Servers use straight-finned
CPU heat sinks,
memory modules and hard drives all lined up from front to back with
airflow running directly over them from front to back.
Servers also usually have fan shrouds that direct air over the
CPU and memory.
Most desktop boards have the memory modules aligned vertically,
basically against the direction of the main front-to-back airflow.
This design may be adequate for relatively cool memory of yesterday,
but seems inadequate and inappropriate for faster, hotter memory of today.
On the other hand servers are meant to
operate with much less concern for noise, and have fans that
constantly run at high rpms. The latter would be unliveable in
a home or office machine. But the fan shroud design from servers
could work in a desktop if the airflow direction was changed.

Inintially I made a memory fan shroud out of a small water bottle.
It was quite effective with a thermally-sensitive fan controller,
but the small fan was very noisy. (The fan came from the 680i
motherboard Northbridge cooler. It's a tiny ADDA AD0512HB-G76.)
Ideally the shroud should expand to a much larger
size to accomodate a large, slow turning fan.
That's what I'm working on now.
The server shrouds are all very close to their components, so
I'm thinking of an acrylic shroud with fans at right angles to the memory,
but offset above the modules.